Cream the butter and sugar. Combine the flour and baking powder; add the flour mixture to the creamed mixture alternately with the milk, beginning and ending with the flour mixture. Stir in the vanilla. Fold the beaten egg whites into the batter.

Pour into 4 greased and floured 9-inch round pans. Bake in a low oven (325 degrees) for about 20 minutes or until a tootpick inserted in the middle comes out clean. Let the cake cool in the pans for 10 minutes; carefully remove them from the pans and let cool. Prepare the Filling. Serves 14-16.

Filling:

Combing the egg yolks, sugar and butter in a saucepan and cook over medium heat, stirring constantly, until thickened (about 20 minutes). Remove from heat and stir in the remaining ingredients. Cool completely before spreading between the cake layers and on top of the cake.

NOTE: This delicious cake is known by other names -- "prairie cake," "amalgamated cake" or "lane cake," but Southerners just call it "good!"